BDNF and epilepsy: In addition to participating in neural remodeling in epilepsy (Fernandez‐Garcia et al., 2020), BDNF secreting projection neurons in vlPAG can also enhance the expression of presynaptic of neuroactive substances such as CGRP, serotonin (5‐HT), and nitric oxide synthase (NOS) by binding presynaptic TrkB in the vlPAG‐RVM pathway to involve in the descending pain modulation (Yin et al., 2014).